What is a snapping shoulder/scapula?

Q:My daughter is 6 1/2 yrs old. The bone joining the shoulder and the left hand makes a sound . Being ambidextrous but more left-handed, her activities are carried out with the same hand. Two years back when we heard this sound, I showed her to an orthopaedician. The X-ray did not show any problem and he said that probably it is a matter of time before the noise stops. The sound still remains. Kindly advise as to what are the various reasons for such a noise to exist?

A:Your daughters condition is often loosely called as snapping shoulder or a snapping scapula. Several conditions are attributed to the causation of this problem. The most common is called exostosis of scapula. This is a condition in which a cartilaginous (the same kind of tissue as in the lining of joints)outgrowth arises from the scapula. This outgrowth rides over the ribs or chest wall as the child moves her arm. This may be difficult to detect as the scapular bone is not easily seen on a shoulder X-ray. It is better appreciated by the palpating with your fingers as the shoulder is moved. So the best diagnosis is by a careful clinical examination. In fact, you may find similar outgrowth on other parts of the body. Look for them.
Less commonly similar snapping sounds may be heard because of irregularities on the gliding surfaces of chest wall and the shoulder blade or between the ball of the shoulder and the shoulder blade. These are more common in adults, may be visible on X-rays.
Tumourous growths other than exostosis may also cause a similar problem.
It is also reported that some anatomical abnormalities may also present with a similar problem.
There are other rare conditions to which can present with a snapping shoulder.
X-rays may not be sufficient. Some surgeons recommend CT Scans to help diagnose. However, this is not recommended as a routine investigation.
To sum up in your childs case the most probable diagnosis would be a snapping scapula as a result of an exostosis. The best way to diagnosis this is by a careful clinical examination. If your surgeon recommends on clinical suspicion then consider a CT Scan.